Mesozooplankton component

1
Mesozooplankton component

• General objective Quantitative assessment of its
  biomass and production and its impacts on
  phytoplankton stocks and vertical matter flux.
•  
• Approaches
• 1. The biomass (as organic carbon and nitrogen)
  determined by combination on size structure
  (estimates based on OPC/ZOOSCAN measurements)
  and direct determination of carbon and nitrogen
  contents(with CHN) in mesozooplankton
  fractions.
•  
• 2. The samples for description of zooplankton
  communities.
•  
• 3. Complementary process studies to estimate
  biological rates (details to be discussed during
  this meeting ) and fluxes through the
  compartment.
• - Egg production experiments
• - Others

• Innovative approach
• Classical approach

2
Details ? Sampling 1. - Bongo net tows for
samples Standard Depth from 200 m to the
surface Alternatives - Depth defined in real
time observation from size particles distribution
UVP (to be discussed). - Open-close nets 2. -
Net tows for living organisms  
3

• ? Processing on board
• 1. Collected samples
• Conditioning samples for preservation
• Conditioning samples for weighting C/N
  filtrations
•  
• 2. Collected living organisms
• 24 h Egg production experiments

4
? Measurement Lab OPC/ZOOSCAN Fine resolution
if the size-structured biomass Binocular Fauni
stic distributions Counting from egg
experiments
5
? Objectives 1. Quantify mesozooplankton
biomass (200 µm-2000 µm) based on a fine
resolution of its size structure using OPC and
ZOOSCAN, and CHN weighting.   Deliverables -      
   Total biomass -         Size-fraction
biomasses (200-300 µm300-500 µm500-1000 µm
gt1000 µm) from OPC/ZOOSCAN and from CHN on
similar size fraction -         Fine
size-distribution of biomass from OPC and
binocular define main contributors
6
? Objectives (suite) 2. Description of
zooplankton communities Deliverables -        
Taxonomic tables per station -        
Identification of main contributors on size
spectra 3. Derived index of zooplankton
production with the slope of the biomass size
spectrum Deliverables -         Index of
production -         Derived fluxes as allometric
relationship to weight Respiration of planktonic
communities by the use of biomass spectra and
allometric relations
7
? Objectives (suite) 4. Estimate
zooplankton production from classical method egg
production of copepods Deliverable Egg
production per female Egg production per biomass
fraction Secondary production